condition mean min max ZT0-3 2.157015 1.695195 3.040765 ZT4-7 1.2377215 1.2377215 1.2377215 ZT8-11 1.44292 1.44292 1.44292 ZT12-15 2.152635 1.99874 2.3065300000000004 ZT16-19 1.52108 1.52108 1.52108 ZT20-23 1.53823 1.53823 1.53823